Question: Subtract.
Explanation: There are many ways to solve this problem. Let's see two ways we can solve it. Place Value We can think in terms of hundredths: $\begin{aligned} &\phantom{=}98- 91.89\\\\ &=98.00-91.89\\\\ &=9{,}800\text{ hundredths} -9{,}189\text{ hundredths}\\\\ &=611\text{ hundredths}\\\\ &=6.11 \end{aligned}$ Place value table Let's line up the numbers by their decimal places. Tens Ones $.$ Tenths Hundredths ${9}$ ${8}$ $.$ ${0}$ $0$ $9$ $1$ $.$ ${8}$ $9$ Now, let's subtract each place value column. Tens Ones $.$ Tenths Hundredths ${9}$ $\overset{7}{\cancel{8}}$ $.$ $\overset{9}{\cancel{0}}$ $\overset{10}{\cancel{0}}$ $-$ $9$ $1$ $.$ ${8}$ $9$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $6$ $.$ $1$ $1$ $6.11 = 98 - 91.89$